mirror of
https://github.com/appgurueu/modlib.git
synced 2024-12-23 05:42:28 +01:00
127 lines
3.1 KiB
Lua
127 lines
3.1 KiB
Lua
-- Localize globals
|
|
local math, math_floor, minetest, modlib_table_reverse, os, string_char, table, table_insert, table_concat
|
|
= math, math.floor, minetest, modlib.table.reverse, os, string.char, table, table.insert, table.concat
|
|
|
|
local inf = math.huge
|
|
|
|
-- Set environment
|
|
local _ENV = {}
|
|
setfenv(1, _ENV)
|
|
|
|
-- TODO might be too invasive
|
|
-- Make random random
|
|
math.randomseed(minetest and minetest.get_us_time() or os.time() + os.clock())
|
|
for _ = 1, 100 do math.random() end
|
|
|
|
negative_nan = 0/0
|
|
positive_nan = negative_nan ^ 1
|
|
|
|
function sign(number)
|
|
if number ~= number then return number end -- nan
|
|
if number == 0 then return 0 end
|
|
if number < 0 then return -1 end
|
|
if number > 0 then return 1 end
|
|
end
|
|
|
|
log = setmetatable({}, {
|
|
__index = function(self, base)
|
|
local div = math.log(base)
|
|
local function base_log(number)
|
|
return math.log(number) / div
|
|
end
|
|
self[base] = base_log
|
|
return base_log
|
|
end,
|
|
__call = function(_, number, base)
|
|
if not base then
|
|
return math.log(number)
|
|
end
|
|
return math.log(number) / math.log(base)
|
|
end
|
|
})
|
|
|
|
-- one-based mod
|
|
function onemod(number, modulus)
|
|
return ((number - 1) % modulus) + 1
|
|
end
|
|
|
|
function round(number, steps)
|
|
steps = steps or 1
|
|
return math_floor(number * steps + 0.5) / steps
|
|
end
|
|
|
|
local c0 = ("0"):byte()
|
|
local cA = ("A"):byte()
|
|
|
|
function default_digit_function(digit)
|
|
if digit <= 9 then return string_char(c0 + digit) end
|
|
return string_char(cA + digit - 10)
|
|
end
|
|
|
|
default_precision = 10
|
|
|
|
-- See https://github.com/appgurueu/Luon/blob/master/index.js#L724
|
|
function tostring(number, base, digit_function, precision)
|
|
if number ~= number then
|
|
return "nan"
|
|
end
|
|
if number == inf then
|
|
return "inf"
|
|
end
|
|
if number == -inf then
|
|
return "-inf"
|
|
end
|
|
digit_function = digit_function or default_digit_function
|
|
precision = precision or default_precision
|
|
local out = {}
|
|
if number < 0 then
|
|
table_insert(out, "-")
|
|
number = -number
|
|
end
|
|
-- Rounding
|
|
number = number + base ^ -precision / 2
|
|
local digit
|
|
while number >= base do
|
|
digit = math_floor(number % base)
|
|
table_insert(out, digit_function(digit))
|
|
number = (number - digit) / base
|
|
end
|
|
digit = math_floor(number)
|
|
table_insert(out, digit_function(digit))
|
|
modlib_table_reverse(out)
|
|
number = number % 1
|
|
if number ~= 0 and number >= base ^ -precision then
|
|
table_insert(out, ".")
|
|
while precision >= 0 and number >= base ^ -precision do
|
|
number = number * base
|
|
digit = math_floor(number % base)
|
|
table_insert(out, digit_function(digit))
|
|
number = number - digit
|
|
precision = precision - 1
|
|
end
|
|
end
|
|
return table_concat(out)
|
|
end
|
|
|
|
-- See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/fround#polyfill
|
|
function fround(number)
|
|
if number == 0 or number ~= number then
|
|
return number
|
|
end
|
|
local sign = 1
|
|
if number < 0 then
|
|
sign = -1
|
|
number = -number
|
|
end
|
|
local exp = math_floor(math.log(number, 2))
|
|
local powexp = 2 ^ math.max(-126, math.min(exp, 127))
|
|
local leading = exp < -127 and 0 or 1
|
|
local mantissa = math_floor((leading - number / powexp) * 0x800000 + 0.5)
|
|
if mantissa <= -0x800000 then
|
|
return sign * inf
|
|
end
|
|
return sign * powexp * (leading - mantissa / 0x800000)
|
|
end
|
|
|
|
-- Export environment
|
|
return _ENV |